src/org/eclipse/jdt/internal/compiler/ast/ThrowStatement.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.compiler.ast;
  12
  13 import org.eclipse.jdt.internal.compiler.ASTVisitor;
  14 import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
  15 import org.eclipse.jdt.internal.compiler.codegen.CodeStream;
  16 import org.eclipse.jdt.internal.compiler.flow.FlowContext;
  17 import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
  18 import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
  19 import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
  20
  21 public class ThrowStatement extends Statement {
  22         public Expression exception;
  23         public TypeBinding exceptionType;
  24
  25         public ThrowStatement(Expression exception, int startPosition) {
  26                 this.exception = exception;
  27                 this.sourceStart = startPosition;
  28                 this.sourceEnd = exception.sourceEnd;
  29         }
  30
  31         public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
  32
  33                 exception.analyseCode(currentScope, flowContext, flowInfo);
  34                 // need to check that exception thrown is actually caught somewhere
  35                 flowContext.checkExceptionHandlers(exceptionType, this, flowInfo, currentScope);
  36                 return FlowInfo.DEAD_END;
  37         }
  38
  39         /**
  40          * Throw code generation
  41          *
  42          * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
  43          * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
  44          */
  45         public void generateCode(BlockScope currentScope, CodeStream codeStream) {
  46
  47                 if ((bits & IsReachableMASK) == 0)
  48                         return;
  49                 int pc = codeStream.position;
  50                 exception.generateCode(currentScope, codeStream, true);
  51                 codeStream.athrow();
  52                 codeStream.recordPositionsFrom(pc, this.sourceStart);
  53         }
  54
  55         public StringBuffer printStatement(int indent, StringBuffer output) {
  56
  57                 printIndent(indent, output).append("throw "); //$NON-NLS-1$
  58                 exception.printExpression(0, output);
  59                 return output.append(';');
  60         }
  61
  62         public void resolve(BlockScope scope) {
  63
  64                 exceptionType = exception.resolveTypeExpecting(scope, scope.getJavaLangThrowable());
  65
  66                 if (exceptionType == NullBinding
  67                                 && scope.environment().options.complianceLevel <= ClassFileConstants.JDK1_3){
  68                         // if compliant with 1.4, this problem will not be reported
  69                         scope.problemReporter().cannotThrowNull(this);
  70                 }
  71                 exception.implicitWidening(exceptionType, exceptionType);
  72         }
  73
  74         public void traverse(ASTVisitor visitor, BlockScope blockScope) {
  75                 if (visitor.visit(this, blockScope))
  76                         exception.traverse(visitor, blockScope);
  77                 visitor.endVisit(this, blockScope);
  78         }
  79 }